Through my studies I have noted a general rule that can help people with knowledge of Spanish differentiate between nouns of the 2nd and 3rd declension. Differentiating between these two declensions is particularly important seeing as the 2nd D. singular genitive is so similar to the 3rd D. dative/ablative plural, which can easily lead to mis-translations.

The trick is that Spanish words that are descended from 2cnd declension nouns mostly end in "o", here are some examples:

Three minor mistakes in your table:* "Pelo" comes from "pilus", not "capillus". "Cabello", however, does come from "capillus".* The Spanish for "parentēs" is "parientes".* The plural of Latin "nōmen" is "nōmina", not "nōminēs", since it's neuter.

Fourth-declension nouns can also wind up in Spanish with -o: manus -> mano, senatus -> senado...

Just for fun to compare French, (written) French helps with corpus and tempus, since it preserved the -s in the singular, corps and temps, but it provides virtually no help at all for the other words (and for some of them I can't find even find any reflexes in French), what with the loss of all post-tonic vowels except a, so there's no difference between ovum > œuf pl. œufs and noctem > nuit pl. nuits.